Khan Academy Biology L3-Biomolecules and Reactions

Flashcards about Biomolecules and Reactions

Biomolecules

Chemical compounds that make up all living organisms, divided into carbohydrates, proteins, nucleic acids, and lipids.

Polymers

Large molecules made up of smaller, repeating parts called monomers.

Carbohydrates

Sugars and sugar polymers made of carbon, hydrogen, and oxygen, storing energy and providing structural support.

Monosaccharides

Simple sugars like glucose, serving as an energy source and monomer for complex carbohydrates.

Polysaccharides

Complex carbohydrates made of hundreds to thousands of monosaccharides, used for energy storage and structure.

Proteins

Diverse biomolecules containing nitrogen, carbon, hydrogen, and oxygen and sometimes sulfur or phosphorus, involved in defense, storage, transport, and more.

Amino acids

Monomers that make up proteins, connected in long chains to form polypeptides.

Polypeptides

Polymers formed by amino acids, folding into a specific 3D structure that determines protein function.

Nucleic acids

Biomolecules made of carbon, hydrogen, oxygen, phosphorus, and nitrogen, including DNA and RNA.

DNA (deoxyribonucleic acid)

Encodes an organism's genetic information.

RNA (ribonucleic acid)

Helps the cell use genetic information to make proteins and carries out regulatory functions.

Nucleotides

Monomers that make up nucleic acids.

Lipids

Organic compounds made of carbon, hydrogen, and oxygen, sometimes with phosphorus, nitrogen, or sulfur, known for being hydrophobic.

Fats

Lipids that store energy, cushion organs, and insulate the body, including saturated and unsaturated types.

Phospholipids

Lipids with a unique structure that allows them to form cell membranes.

Steroids

Lipids found in cell membranes that function as chemical messengers, regulating biological processes.

Chemical reaction

A process where substances (reactants) change to form new substances (products).

Reactants

Substances that undergo change in a chemical reaction.

Products

New substances formed in a chemical reaction.

Endothermic reactions

Reactions where more energy is absorbed to break bonds than released when new bonds are formed, resulting in an overall absorption of energy.

Exothermic reactions

Reactions where more energy is released when new bonds are formed than used to break bonds, resulting in an overall release of energy.

Metabolism

The thousands of chemical reactions that occur in cells to keep an organism alive.

Metabolic pathway

A series of connected chemical reactions where the products of one reaction become the reactants in the next.

Anabolic pathways

Pathways that build up biomolecules and result in an overall absorption of energy.

Catabolic pathways

Pathways that break down biomolecules and result in an overall release of energy.

Activation energy

The amount of energy needed for a chemical reaction to start.

Catalyst

A substance that speeds up a chemical reaction by providing an alternative pathway that requires less activation energy.

Enzymes

Proteins that act as biological catalysts, speeding up chemical reactions in cells.

Substrates

Reactant molecules that bind to an enzyme.

Active site

The part of the enzyme where the substrate binds.

Biomolecules

Organic compounds in food that store energy.